I am in Australia and use a 28 Degrees Mastercard for competitive exchange rate and no conversion fees.

That said, like Zandel, it has been a long time since I have bought any NG.

You could always set a low credit limit on the credit card if you are fearful of being scammed. I have had my credit details stolen once, and it was my bank who alerted me of the unusual transactions and asked if I made them - the bank reimbursed me very quickly.